A feeding device includes a material rack configured to support a carrier board, a ratchet mechanism disposed outside the material rack, a locking mechanism disposed outside the material rack, and a triggering mechanism. The locking mechanism can engage with the ratchet mechanism. The triggering mechanism an drive the ratchet mechanism to move back and forth in a first direction, thereby controlling the locking mechanism to move back and forth in a second direction different from the first direction, so that the material rack alternates between a locked state and an unlocked state.